College Profile 2023

NORTHERN LIGHTS

Clemson-led research teams

launch rockets

into aurora borealis to study energy

A s the Northern Lights danced over Poker Flat Research Range near Fairbanks, Alaska, early one morning in April, a team of researchers led by Clemson University assistant professor of physics Stephen Kaeppler launched a sounding rocket into the colorful aerial display. Three minutes later, the scientists launched a second rocket. The researchers launched the rockets to study how energy behaves during an active aurora as a part of the NASA-funded research project titled “Ion-Neutral Coupling During Aurora,” or INCAA. The upper layers of the Earth’s atmosphere are composed of a neutral component — the thermosphere — and an ionized component — the iono sphere. The ionosphere responds to forces of the magnetosphere, which is plasma trapped in the Earth’s magnetic field and forming a shield that pro tects the Earth from solar winds. This plasma can eventually move along the earth’s magnetic field near the poles and collide with oxygen, nitrogen and other gaseous particles in the thermo

sphere. The result of these interactions causes the aurora borealis’ beautiful displays of light. Kaeppler and colleagues from the University of

rapidly in space and time. There are a lot of dynamics happening during an aurora.” Scientists launched the rockets in the last hours of a 16-day launch window. Once the first sounding rocket reached an altitude of 80 miles, it released several vapor tracers at 3-mile increments. Vapor tracers are colorful chemicals similar to those used in fireworks shows that allow scientists to observe the movement of winds. The second rocket carried scientific instruments to collect data.

Alaska-Fairbanks, University of Cal

ifornia-Berkeley and University of Calgary are studying how and at

what altitude energy from the magnetosphere is transferred to the ionosphere and thermosphere. The ionosphere and thermosphere regions are about 50 miles to 400 miles above the Earth’s surface. They also want to determine if the interaction of the thermosphere with the overlapping ionosphere affects the transfer location. “A good analogy is rubbing your hands together. When you do that, you get friction, and with friction, you get heating. So there’s energy transferred back and forth,” Kaeppler said. “It’s the same concept here, except we’re deal ing with gases. Ultimately, the rocket is trying to study how this energy transfer occurs, especially during more active conditions when things are changing

Scientists are still analyzing the data, but their findings could lead to a greater

understanding of space weather factors that affect satellites in low-Earth orbit.

‘Ultimately, the rocket is trying to study how this energy transfer occurs, especially during more active conditions when things are changing rapidly in space and time.’

Assistant Professor Stephen Kaeppler